Started from the control logic of oil-gas separation central control system for offshore oil and gas platform, the control model of main components of oil-gas separation system is simplified and extracted, and the originally complicated flow function and volume function are approximated with piecewise linear function to reduce the difficulty of analog simulation. The operation simulation of oil-gas separation central control system for offshore oil and gas platform in Unity3D can provide necessary support for the research and development of offshore oil and gas platform.